Pyelitis as an obstetric complication should include not only the cases that occur during pregnancy, but also the cases that begin during the puerperium. Although the cases that occur during pregnancy outnumber those beginning in the puerperium, it seems desirable that they should be discussed together.
Pyelitis occurring during pregnancy assumes a more serious aspect than does a simple case of pyelitis, since it concerns not only the patient, but the fetus as well, and, moreover, may influence unfavorably the course of the pregnancy.
Some of the predisposing causes are common both to simple pyelitis and to the pyelitis of pregnancy. In addition to these causes, there are certain predisposing factors which are directly due to, or associated with, the pregnancy.
Lesions of the Gastro-Intestinal Tract.
—It has repeatedly been pointed out that lesions of the gastro-intestinal tract are most important predisposing factors; constipation undoubtedly heads the list.
KRETSCHMER HL. PYELITIS OF PREGNANCY. JAMA. 1923;81(19):1585-1589. doi:10.1001/jama.1923.02650190015004